Window escape descent control device

Abstract

The window escape descent control device for emergency use from upper windows of tall buildings comprises a body harness supported on the end of a rope wound around a flanged spool. The spool, when turned by the unwinding rope pulled by the weight of an escaper in the body harness, turns the shaft and an electrical generator operatively mounted thereon. The shaft also carries, and is controlled by, an electromagnetic brake and a speed control governor, which may be either centrifugally or optically operated and which, when a predetermined rate of shaft rotation is reached, causes energy to be released from the generator to actuate and apply the brake to the shaft; thus the rate off all of the escaper cannot exceed a pre-selected maximum. The mechanism is mounted on a frame support structure straddling and depending from the escape window ledge. The frame strucutre provides hand and foot support to aid the escaper in climbing out the window and in getting into position for descent. Means for rewinding the rope onto the spool for another escape descent from the same window is also provided.

What is claimed is: 
     
       1. Window escape descent control device for lowering an escaper from an upper window of a high building at a safe predetermined maximum rate of descent, which comprises: body support means for holding the escaper securely during the descent from window to ground;   a main rope attached to said body support means, said main rope being of sufficient length to reach from window to ground;   a spool on which said main rope is wound;   a shaft coaxially carrying, and for simultaneous rotation with, said spool;   speed control means operatively mounted on said shaft for governing the maximum speed of rotation of said shaft when said spool is rotated by the unwinding of said main rope from said spool by the weight of the descending escaper; and   frame support means to be secured on the ledge of the escape window for providing mounting for said speed control means, said spool and said shaft, said frame means also providing hand and foot supports to aid the escaper in emerging from the window and positioning himself for descent.   
     
     
       2. Window escape descent control device in accordance with claim 1, wherein said body support is a harness which comprises: an adjustably secured waist-encircling belt;   a second belt supporting the upper body extending around the chest and under the arms of the escaper;   a support rope connecting the rear portions of said waist belt and said second belt; and   means for connecting said second belt and said support rope to said main rope.   
     
     
       3. Window escape descent control device as defined by claim 1, wherein said spool is provided with one-way rotation control means for said main shaft to be turned by the rotation of said spool in only one direction. 
     
     
       4. Window escape descent control device as defined by claim 1, wherein said spool comprises a stepped diameter rope-winding portion to alter the amount of said main rope being unwound per revolution of said spool. 
     
     
       5. Window escape descent control device in accordance with claim 1, wherein said speed control means comprises: a generator mounted operatively on said shaft for converting the rotational energy from said shaft to electrical energy;   electromagnetic brake means operatively mounted on said shaft for slowing the rotation of said shaft when said brake means is energized by the electrical energy supplied by said generator; and   speed governing means operatively connected to said shaft for actuating said electromagnetic brake by closing the circuit between said generator and said brake when the rotation of said shaft reaches a pre-determined maximum speed.   
     
     
       6. Window escape descent control device in accordance with claim 5, wherein said speed governing means comprises a centrifugally activated mechanism operated by the rotation of said shaft for controlling the closing of a circuit-completing switch by centrifugal force. 
     
     
       7. Window escape descent control device as defined by claim 5, wherein said speed governing means is optically controlled. 
     
     
       8. Window escape descent control device as defined by claim 1, further comprising means for rewinding said main rope on said spool to permit the descent control device to be used by another escaper after the first escaper has reached the ground. 
     
     
       9. Window escape descent control device as defined by claim 1, wherein said frame means further comprises: adjustment means for permitting said frame support means to be mounted firmly on the window ledge and against the building wall extending below the escape window; and   said frame support means being formed from a plurality of pivotally connected sections to be folded on one another for facilitating storage of the window escape descent control device.